I've been a minor league card collector from the beginning, when TCMA came out with sets in the 1970's.
Certainly, the holy grails of Orioles minor league sets are the 1980 Charlotte O's blue SGA set and the O's orange Police set. Both of those sets contain coveted Cal Ripken Jr cards. I'm lucky to have the complete blue set, but only 9 cards from the orange set and no Ripken. At the prices the orange Ripken command, I'll probably never finish the set, but do look for nice examples of the others. I do have the John Shelby, Drungo Hazewood and Willie Royster cards, which are three of the guys to play for the Orioles.
Two of my other favorite sets also feature the Charlotte O's. While not extremely expensive, both sets are somewhat hard to find. Both sets contain a sampling of future Orioles players.
The 1981 set issued by the team looks very similar to the 1980 orange Police set. I see attempts to pass these off as the 1980 cards. The main difference is that the backs are much different and don't have tips from the Police Dept like the 1980 set.
1981 Charlotte O's team issued set
1981 Team Charlotte O's #1.jpg 1981 Team Charlotte O's #2.jpg 1981 Team Charlotte O's #3.jpg s-l400.jpg
The 1982 set has a nice design. It's labeled as "Heroes Aren't Hard to Find". Again the set can be had at a reasonable price if you can find one.
1982 Charlotte O's Heroes set
1982 Heroes Charlotte O's #1.jpg 1982 Heroes Charlotte O's #2.jpg 1982 Heroes Charlotte O's #3.jpg 1982 Heroes Charlotte O's #4.jpg